WO2007111121A1

WO2007111121A1 - Electrostatic atomization device

Info

Publication number: WO2007111121A1
Application number: PCT/JP2007/054908
Authority: WO
Inventors: Hiroshi Suda; Takayuki Nakada; Masaharu Machi
Original assignee: Matsushita Electric Works, Ltd.
Priority date: 2006-03-29
Filing date: 2007-03-13
Publication date: 2007-10-04
Also published as: TW200800405A; TWI324088B

Abstract

A high voltage is applied to a liquid fed to a discharge electrode, thereby to charge the liquid into minus, so that the mist of minus-charged fine particles is released from the discharge electrode into a target space. A minus high voltage is intermittently applied to the discharge electrode, and the minus charge left in the target space is eliminated for a quiescent period of no minus potential application, so that the mist of minus-charged fine particles is continuously released into the target space.

Description

Specification

Electrostatic atomizer

Technical field

The present invention relates to an electrostatic atomizer that discharges a mist of negatively charged liquid fine particles, and more specifically, an electrostatic atomizer that can stably provide a negatively charged mist to a target space. It is about.

Background art

[0002] Japanese Patent Publication (JP-A-2005-131549) discloses an electrostatic atomizer that generates negatively charged fine particle water mist by electrostatically atomizing water. In this device, the water supplied to the discharge electrode forms a tiller cone at the tip of the discharge electrode, which causes the Rayleigh splitting to atomize and atomize the nanometer order negative ion charged fine particle water. Mist (negative ion mist) is generated. This mist contains radicals and has a long life, can diffuse a large amount into the space, adheres to and penetrates the objects present in the release space, and effectively sterilizes and deodorizes. Can do.

[0003] However, when this electrostatic atomizer is installed in a narrow target space such as a food storage, for example, negative ion mist is released into the target space over a long period of time. Causes a problem that it is difficult to stably generate the negative ions. This is because negatively charged fine particles adhere to the inner wall of the food storage housing that surrounds the target space and the surface of the substance stored here, and the above-mentioned tiller cone at the tip of the discharge electrode influences this negative potential. In view of this, it is considered that the cause is that it is difficult to form a stable tiller cone.

Disclosure of the invention

[0004] The present invention has been invented in view of the above problems, and can negatively charge fine particle mist stably over a long period of time without being affected by the negative charge remaining in the target space. An object of the present invention is to provide an electrostatic atomizer.

[0005] An electrostatic atomizer according to the present invention includes a discharge electrode and a liquid for supplying a liquid to the discharge electrode. A body supply means and a high voltage that applies a high voltage to the discharge electrode to charge the liquid sent to the tip of the discharge electrode to the negative electrode and release a negatively charged fine particle mist from the tip of the discharge electrode Source. A feature of the present invention is that it includes a controller that controls a high voltage source so that a high voltage of a negative potential is intermittently applied to the discharge electrode. For this reason, during the rest period in which no negative potential is applied to the discharge electrode, negative charges existing in the target space are spontaneously discharged, and negatively charged fine particle mist can be stably discharged over a long period of time.

[0006] Preferably, the electrostatic atomizer of the present invention is provided with humidity detecting means for detecting the ambient absolute humidity. The controller applies a negative potential as the absolute humidity increases. Thus, the ratio of the idle period during which no negative potential is applied is configured to be small. The negative charge existing in the target space increases the amount of spontaneous discharge per unit time as the absolute humidity rises.Therefore, depending on the situation of the target space, the negative charge fine particle mist is set to the optimum value for the rest period. It can be generated efficiently.

[0007] Further, the controller may be configured to alternately repeat a first operation mode in which the discharge electrode has a negative potential and a second mode in which the discharge electrode has a positive potential. In this case, by discharging the positively charged charged fine particles during the rest period in which no negative potential is applied, the negative charge existing in the target space can be neutralized, and the discharge of the negatively charged fine particle mist is stabilized. Can continue.

[0008] In addition, the electrostatic atomizer of the present invention may include an ionization needle to which a positive potential is applied. In this case, the controller is configured to generate a positive ion from the tip of the ionization needle by applying a high voltage to the ionization needle during a period when the discharge electrode is not applied negatively, and exists in the target space. Neutralize negative charges and release stable negative charged mist.

[0009] Furthermore, the ratio of the period during which positive ions are released from the discharge electrode ionization needle to the operation period during which negative charged fine particle mist is generated is set smaller by the controller as the absolute humidity increases. It is preferable.

Brief Description of Drawings

FIG. 1 is a schematic diagram showing an electrostatic atomizer according to an embodiment of the present invention. FIG. 2 is an explanatory view showing one usage pattern of the electrostatic atomizer.

FIG. 3 is an explanatory diagram showing the operation of the electrostatic atomizer described above.

FIG. 4 is a perspective view of the electrostatic atomizer described above.

FIG. 5 is a perspective view with the cover removed.

FIG. 6 is an explanatory view showing the operation in a modified embodiment of the electrostatic atomizer.

FIG. 7 is a schematic view showing an electrostatic atomizer according to another embodiment of the present invention.

FIG. 8 is an explanatory view showing the operation of the electrostatic atomizer described above.

BEST MODE FOR CARRYING OUT THE INVENTION

[0011] The electrostatic atomizer according to the present invention generates a mist in which negatively charged fine particles of nanometer order and negatively charged fine particles of micron order are mixed. By discharging this mist to the target space, the target is obtained. It is used to deodorize, sterilize, and decompose substances present in the space and to provide appropriate humidity. For example, when incorporated in a food storage 90 as shown in Fig. 2, the active species contained in nanometer-order negatively charged fine particle mist sterilize food and decompose harmful substances attached to food. At the same time, the freshness is maintained by keeping the humidity in the storage 90 at an appropriate value with minus-charged fine particle mist of micron order.

As shown in FIG. 1, an electrostatic atomizer according to an embodiment of the present invention includes a foggy horned nose 10 whose tip is a discharge electrode 20, and a counter electrode disposed to face the discharge electrode 20. 30, a high voltage source 60 that applies a high voltage between the discharge electrode 20 and the counter electrode 30, and a controller 70 that controls the value of the high voltage. A pressure tank 40 is connected to the rear end of the atomization nozzle 10, and a liquid, for example, water stored in the pressure tank 40 is supplied to the tip of the discharge electrode 20 through the atomization nozzle 10. This pressurized tank 40 forms a liquid supply means for supplying liquid to the discharge electrode 20. The electrostatic atomizer of the present invention can use various liquids in addition to water, but in the present embodiment, description will be made based on an example in which water is used as the liquid.

[0013] The water supplied to the tip of the discharge electrode 20 becomes a liquid ball due to surface tension, and by applying a high voltage, for example, a negative potential of 8 kV, to the discharge electrode 20, the discharge end at the tip of the discharge electrode 20 and the counter electrode A high voltage electric field is generated between 30 and this liquid ball is charged with static electricity, Discharged from the tip of the discharge electrode as mist M of charged fine particles of water charged negatively. When a high voltage is applied between the discharge electrode 20 and the counter electrode 30, a Coulomb force acts between the water held at the tip of the discharge electrode 20 and the counter electrode 30, and the surface of the water is localized. As a result, the tiller cone TC is formed. Then, the electric charge is concentrated at the tip of the tiller cone TC, and the electric field strength in this portion increases, and the Coulomb force generated in this portion increases, and the tiller cone TC is further grown. After that, when the Coulomb force exceeds the surface tension of the water W, the tiller cone repeats splitting (Rayleigh splitting), generating a large amount of nanometer-order charged fine particle water mist. This mist is released in such a way that it passes through the counter electrode 30 in the air flow caused by the ion wind flowing from the discharge electrode 20 toward the counter electrode 30.

[0014] Water is supplied to the pressurization tank 40 from the replenishment tank 50 by the pump 52, and the water level in the pressurization tank 40 is controlled to be always constant, so that the water supplied to the tip of the discharge electrode 20 is equal. A constant water head pressure is applied. For this reason, the pressurized tank 40 is provided with a level sensor 42 and the pump 52 is controlled by the controller 70 so that the water level detected by the level sensor 42 is always constant.

[0015] The atomizing nozzle 10 is formed of a tubular body, and the tip portion forming the discharge electrode 20 becomes a capillary tube, and the inner diameter of the portion from the pressure tank 40 at the rear end to the discharge electrode 20 at the tip causes capillary action. It is set so as not to rub, and the water head pressure acts on the liquid droplets of water supplied to the tip of the discharge electrode 20. The inner diameter of the atomizing nozzle 10 gradually decreases toward the tip portion that becomes a capillary, and water becomes a liquid ball due to surface tension at the tip of the discharge electrode that is a capillary. This hydraulic head pressure is set to a value that does not hinder the formation of liquid balls due to surface tension, and this hydraulic head pressure acts on the tiller cone TC that is formed when a high voltage is applied.

[0016] By the way, the force that maintains the shape of the Tiller Cone TC by the surface tension. When the above-mentioned hydraulic head pressure is applied to the Tiller Cone TC, the Tiller Cone can be applied to the surface other than the most advanced surface where charges are concentrated by applying a high voltage. A part of the surface is torn, splits and scatters. In other parts of the tiller cone, the charge is not concentrated as much as the leading edge, so the energy that breaks up the water is also reduced, and as a result, negatively charged fine particle mist of the order of microns is generated. . Therefore, pressurized water is supplied to the tip of the discharge electrode 20. By applying a high voltage to the tip while applying a force, as described above, negatively charged fine particle mists that are split from the tip of the Tiller Cone TC and other than the tip of the Tiller Cone TC A mist of negatively charged fine particles of micron order, which is generated by splitting from this part, is generated. The mist mixed with these negatively charged fine particles is discharged into the space in a diffused state, and water is continuously supplied to the discharge electrode 20 by the applied pressure, so that the mist is generated continuously.

[0017] The nanometer-order negatively charged fine particle mist contains active species (radicals), and these radicals sterilize and deodorize substances present in the space or decompose harmful substances. Micron-order negatively charged fine particles are diffused into the space and humidified

[0018] By changing the pressure applied to the discharge electrode 20, adjustment of the particle size distribution of the negatively charged fine particle mist of the nanometer order and the negatively charged fine particle mist of the micron order and the generation amount of the negatively charged fine particle mist of the nanometer order And the ratio of the generation amount of negatively charged fine particle mist on the order of microns can be adjusted. That is, by adjusting the water head pressure depending on the water level in the pressurized tank 40, the particle size distribution and the ratio of the generated amount can be selected, and the charged fine particles of nano order and micron order can be selected depending on the usage. It is possible to generate mixed mist that is optimally combined.

In the present invention, the nanometer order is a range of 3 nm or more and lOOnm or less, and the micron order is a range of more than 0.1 / im and 10 μΐη or less.

[0020] In the electrostatic atomizer of the present invention, the controller 70 is configured to intermittently generate mist of negative charged fine particles from the tip of the discharge electrode 20, and the power switch 94 is turned on. As shown in FIG. 3, the controller 70 alternately repeats the operation period T1 in which the high voltage V1 having a negative potential is applied to the discharge electrode 20 and the pause period T2 in which no voltage is applied. During the rest period T2, the release of mist of negatively charged fine particles is interrupted, so that negative charges attached to the wall surface of the target space and the surface of the substance in the target space are extinguished by natural discharge. The For this reason, the tiller cone formed at the tip of the discharge electrode 20 can maintain a stable shape that is not affected by a strong negative charge from the target space, and the mist of the negatively charged fine particles can be stably maintained over a long period of time. Can be released into the target space. The

[0021] The operation period Tl and the pause time T2 are appropriately set so that the negative charge in the target space disappears to such an extent that the shape of the tiller cone does not become unstable due to natural discharge during the pause period. For example, when a target space with a volume of 70 L is formed by a polystyrene housing having a volume resistivity of 10 ¹⁶ to 10 ² ° (Ω 'cm), it is preferable that Tl / T2 <= 6/1 .

In addition, the electrostatic atomizer of the present embodiment is provided with a humidity sensor 72 that is a humidity detecting means for detecting the absolute humidity in the target space, and the controller 70 operates as the absolute humidity increases. It is configured to reduce the ratio of the rest period Τ2 to the period T1. When absolute humidity increases, spontaneous discharge of negative charges in the target space S is promoted, so that a mist of negatively charged fine particles is efficiently generated with an optimal period of Τ2 according to the conditions of the target space. I can do it.

[0023] As shown in FIGS. 4 and 5, each component constituting the electrostatic atomizer is incorporated in the housing 100. The housing 100 includes a base 110 and a cover 120 covering the base 110, and an atomizing nozzle 10, a replenishing tank 50, and a pump 52, which are integrated with the pressurized tank 40, are attached to the base 110. The discharge electrode 20 and the counter electrode 30 are exposed to the outside of the housing 100. The electrical components constituting the high-voltage power supply 60 and the controller 70 are accommodated in the housing 100. A window 122 is formed on the cover 120, and the water level in the replenishing tank 50 formed of a transparent material can be confirmed through the window 122. The supply tank 50 is provided with a cap 54 to add water as needed.

In the illustrated embodiment, the force shown in the example in which the counter electrode 30 is provided in front of the discharge electrode 20 and a high voltage is applied between the discharge electrode 20 and the counter electrode 30 is not necessarily limited to the present invention. For example, it is possible to apply a high voltage to the discharge electrode 20 by using a part of the housing 100 as a ground electrode. In this case, the surrounding air becomes a dotted potential, and the charged fine particles Mist can be discharged from the tip of the discharge electrode 20.

[0025] As shown in FIG. 2, when the electrostatic atomizer of the present invention is incorporated in a food storage 90 for storing food such as vegetables, it is used as an active species contained in nano-order charged fine particle mist. (Radical) sterilization of food, deodorization, and harmful substances such as agricultural chemicals contained in food In addition to being decomposed, it is possible to maintain the internal humidity at an appropriate level with micron-order charged fine particle mist. In particular, when storing vegetables, freshness of the vegetables can be maintained by supplying a large amount of micron-order charged fine particles into the vegetable tissue through the pores of the vegetables.

[0026] The food storage 90 includes a temperature adjusting unit 92 for maintaining the inside at a predetermined temperature, and a power switch 94 and a temperature adjusting button 95 are provided on the outer surface. The electrostatic atomizer is operated by a power switch 94, and charged particles mist of nanometer order and charged particle mist of micron order are discharged into the storage chamber 91.

[0027] In vegetables, leafy vegetables cannot maintain their freshness by simply humidifying the surface of the leaves, but can maintain freshness by supplying moisture into the leaf tissue from the pores of the leaves. Are known. The stomata of leafy vegetables is about 100-200111 on the long side and about 10 μΐη on the short side. Nanometer-order charged fine particles can penetrate into leaf tissue from leafy vegetable pores Nanometer-order charged fine particle mist has a very small particle size, so the amount of water necessary to maintain the freshness of leafy vegetables Insufficient supply inside the organization. However, micron-order charged microparticles retain more water than nanometer-order charged microparticles mist, so that a sufficient amount of water can be replenished by entering the leaf tissue through the pores. Can maintain freshness. For this reason, when an electrostatic atomizer is installed in a food storage, the peak of the particle size distribution of the number of generation of micron-order charged fine particles is 以下 μ ΐη or less, preferably 0.5 / im to 1.5 / Adjust the applied pressure and applied voltage so as to be im.

[0028] Nanometer-order charged fine particle mist sterilizes and deodorizes the surface of leafy vegetables and removes harmful substances such as pesticides adhering to leafy vegetables from the pores. Can be sterilized, deodorized in the tissue, and decomposed inside the pesticides. In this case, the particle size distribution peak of the number of charged fine particle mist of nanometer order is 3 nm to 50 nm. Adjust the applied pressure and applied voltage so that

[0029] FIG. 6 shows a modification of the above-described embodiment. By applying a positive potential (for example, +8 kV) to the discharge electrode 20 in a rest period T2 in which negatively charged fine particles are not released, Controller 70 is configured to release positively charged particulate mist. In this case, the counter electrode 30 is set to the ground potential (0 V) during the operation period T1 and the rest period T2, and positive and negative high voltages are alternately applied to the discharge electrode 20. The positively charged fine particles generated during the rest period T2 neutralize the negative charge remaining in the target space S, so that a mist of negatively charged fine particles is released into the target space over a long period of time.

[0030] FIG. 7 shows an electrostatic atomizer according to a second embodiment of the present invention. This electrostatic atomizer has basically the same configuration as that of the first embodiment except that an ionization needle 80 that emits positive ions is added to the target space S, and the same members have the same numbers. Indicated by

[0031] A positive voltage of about +8 kV is applied to the ionization needle 40 from a high voltage source 62 provided separately from the high voltage source 60 for applying a negative voltage to the discharge electrode 20 under the control of the controller 70. Thus, corona discharge is generated, and thereby positive ions are released into the target space S. As shown in FIG. 8, the controller 70 applies a negative high voltage VI to the discharge electrode 20 during the operation period T1 to generate mist of negatively charged fine particles, and during the rest period T2, the ionization needle 80 Apply positive voltage V2 of Heplus potential to generate positive ions. Since these positive ions neutralize the negative charge remaining in the target space S, a mist of negatively charged fine particles is continuously generated. The high voltage applied to the ionization needle 80 can be taken out from the high voltage source 60 without using another high voltage source 62.

[0032] Also in this embodiment, the humidity sensor 72 that detects the absolute humidity of the target space S is used, and the controller 70 reduces the ratio of the pause period T2 to the operation period T1 as the absolute humidity increases. Composed. As a result, an optimum static elimination effect can be obtained according to the humidity condition of the target space. In other words, the neutralization of positive ions can be effectively combined with the neutralization of positive ions by utilizing the fact that spontaneous discharge of negative charges remaining in the target space is promoted when the humidity in the target space increases. In addition, it becomes possible to continuously and stably release the mist of the negatively charged fine particles.

Note that various types of humidity sensor 72 can be applied. For example, it is acceptable to use an object that calculates the absolute temperature from the temperature and relative humidity in the target space S. Also electrostatic The absolute temperature is changed from the relative temperature on the condition that the target space S is maintained at a substantially constant temperature as in the case where the atomizer is used for a device that is maintained at a constant temperature such as a food storage. The detection format can be used. Further, a type that detects the absolute temperature from the temperature can be used as long as the target space S is maintained at a substantially constant humidity.

[0034] In the above embodiment, the case where the electrostatic atomizer of the present invention is used in the food storage 90 is illustrated, but other than this, for example, it can be applied to a washing machine, a clothes dryer, and a tableware dryer. Is possible.

[0035] Furthermore, in the above-described embodiment, the force showing the configuration for generating negatively charged fine particle mist of nanometer order and negatively charged fine particle mist of micron order from the discharge electrode 20 The present invention is not necessarily limited to this. A configuration that generates only nanometer-order charged fine particle mist may be adopted. Furthermore, as the liquid to be electrostatically atomized, in addition to water, for example, a liquid made of an antibacterial agent or a disinfectant can be used.

Claims

The scope of the claims

[1] a discharge electrode;

Liquid supply means for supplying a liquid to the discharge electrode;

A high voltage source for applying a high voltage to the discharge electrode to charge the liquid sent to the tip of the discharge electrode to a negative electrode and discharging charged particle mist charged negatively at the tip force of the discharge electrode;

An electrostatic atomizer, comprising: a controller that controls a high voltage source so that a negative high voltage is intermittently applied to the discharge electrode.

[2] Humidity detection means for detecting the absolute humidity of the surroundings is provided, and the controller does not apply a negative potential to the operating period in which a negative potential is applied to the discharge electrode as the absolute humidity increases. The electrostatic atomizer according to claim 1, wherein the ratio of is reduced.

[3] The electrostatic controller according to claim 1, wherein the controller alternately repeats a first operation mode in which the discharge electrode has a negative potential and a second mode in which the discharge electrode has a positive potential. Atomization device.

[4] Humidity detection means for detecting ambient absolute humidity is provided, and the controller reduces the ratio of the second mode period to the first mode period as the absolute humidity increases. The electrostatic atomizer according to claim 3.

[5] An ionization needle to which a positive potential is applied is provided, and a high voltage is applied to the ionization needle during a period in which the discharge electrode is not applied to the negative, so that the tip force of the ionization needle also generates positiveness. The electrostatic atomizer according to claim 1, wherein the apparatus is an electrostatic atomizer.

[6] Humidity detection means for detecting the ambient absolute humidity is provided, and the controller moves the ionization needle during the operation period in which a negative potential is applied to the discharge electrode as the absolute humidity increases. 6. The electrostatic atomizer according to claim 5, wherein a ratio of a period for applying the positive potential is reduced.